1. Field of the Invention
The present invention relates to a folding machine of a rotary press and, more particularly, to a folding machine which uses full-size travelling web (hereinunder referred to as "W-width web") the width of which corresponds to that of a 4-page newspaper, which uses no turning bars but other means for arranging the lateral position of the travelling web, gathering the slit webs or changing their route of travel, which is suitable for printed matter having many pages with each copy folded into several sections, and further which is capable of incorporating a color printed page into a desired position.
2. Description of the Prior Art
In this age of mass communication, there is a tendency to increase the number of pages contained in a single newspaper. In Japan, one newspaper consists of, for example, a 24- page section ("section" means one gathering unit), or two sections comprising 16 outside pages and 8 inside pages. In foreign countries, e.g., in America, the number of pages is further increased, for example, one newspaper may consist of a 40-page section (see FIGS. 3(C) and 7(C)), or two sections consisting of 28 outside pages and 12 inside pages, while sometimes newspaper printing is performed for a newspaper having three or four multi-page sections, such as 60 or 80 pages, per copy. In such newspaper printing, it is very important that however many pages or sections go to make up one newspaper, each newspaper must be made into one bundle in the delivery portion during the final process of newspaper printing so that it may be distinguished from others, because ambiguity would otherwise arise as to the unit represented by one newspaper since this is the fundamental unit for conveyance purposes.
The most conspicuous feature of the present invention is the development of a folding machine which can meet the demand for production of newspapers having a great number of pages. Although a conventional folding machine can meet such a demand, as will be described later, the present invention is distinguishable from the prior art in that it does not use any turning bar.
When newspapers having, e.g., a 40-page section per copy thereof (see FIG. 3(C)) are produced by a conventional folding machine, W-width travelling webs W1, W2, W3, W4 and W5 are fed to five single-color perfecting press units PU1, PU2, PU3, PU4 and PU5, respectively, which are disposed in parallel to each other, as shown in FIGS. 1 and 3. After printing is conducted on both sides, they are introduced to respective W-width drag rolls 25, where each printed web is longitudinally divided into two half-size webs (equivalent to the width of 2 pages) by a slitter knife 26 which is provided at the central portion of each roll in such a manner that its edge comes freely into and out of contact with the roll. One of these half-size slit webs, an upper half-size web in FIGS. 1 and 3, is fed directly to a folding machine, while the other half-size web is introduced to a turning bar mechanism 27 composed of a pair of bars arranged in parallel to each other at a position 45 degrees from the web to arrange the lateral position of webs. The turning bar mechanism 27 rotates the introduced half-size web such that the route of travel thereof agrees with that of the upper half-size web.
Thus, ten half-size webs with one placed on top of another are introduced into a right-hand side former 28R alone, as shown in FIG. 3(B), passed through a cross folder 29, and are discharged on a conveyor 30 in the form of a 40-page section newspaper 37 (FIG. 3(C)).
In a conventional W-width former folder, a slitter knife 32 is provided at the center of a drag roll 31 having a length of W-width such that the edge thereof freely comes into and out of contact with the roll. A pair of 1/2 W-width formers 28L and 28R are provided along the roll, a pair of 1/4 W-width forming rolls 33 and 34 are provided right under the formers 28L and 28R, respectively, and further, below the 1/4 pairs of W-width forming rolls, a pair of 1/2 W-width nipping rolls 35 and 36 are respectively disposed. Thus, as described above, the conventional folder has no mechanism for stacking a 1/2 W-width web travelling on one side on top of that travelling on the other side, and this function is left entirely to the turning bar mechanism.
The turning bar mechanism will now be discussed. A turn bar is, as is known, a rod which does not rotate, and the travelling web is made to slide along the peripheral surface thereof at a high speed and thus to turn toward a different direction. Sometimes, during this movement, the web is smeared when the printed surface with incompletely dried ink thereon is rubbed against the bar, or creases are produced on the web surface, thereby increasing the ratio of spoilage. At other times, creases lead to breakage of paper, which requires much labor and time for stopping all the operations of the machine, removal of the broken paper, re-insertion of a web, etc., and many materials are wasted, thereby reducing productivity to a considerable extent. In addition, the adjustment of the unbalanced tension between the travelling web which has passed through the turning bars and the one which has not passed therethrough is difficult, which constitutes an obstruction to high-speed operation, automatization, saving of man power, simplification of the structure and reduction in cost.
The aforementioned disadvantages also apply to formation of newspapers 38 having two sections of 28 outside pages and 12 inside pages per copy by a rotary press provided with a conventional folding machine, as shown in FIG. 4. A W-width web is longitudinally divided into two half-size webs by the slitter knife 26 on the drag roll 25. With respect to the uppermost travelling web W5 and the second uppermost travelling web W4 it is required that one of the half-size webs is introduced into the turning bar mechanism 27 to travel on the same route as the other half-size web. Thus, the above-described troubles caused by the use of the turning bar mechanism cannot be avoided.
With the progress of printing techniques, color-printed pages have recently been provided as well as single-color printed pages.
However, it is still not possible in terms of equipment and cost to realize coverage of all the pages of a newspaper with color printing. At present, color printing is often provided for the first page which is likely to attract the most attention. Nevertheless, the first page is usually filled with lead stories having news value, and is not always suitable for color printing which shows rather more artistic features. Thus freedom of arrangement when it is desired to incorporate color printing into any given page has been in demand.
Conventionally, the turning bar mechanism is also used for rearrangement of pages. As shown in FIG. 23, a satellite type color press unit LST is disposed at a position after the three single-color perfecting press units PUl, PU2 and PU3 and a former folder RF is disposed at the extreme downstream end. The travelling web W3 which is discharged from the adjacent single-color press unit PU3 is introduced to the color press unit LST, and all the travelling webs are simultaneously folded by the former folder. At this time, if the color printed portion (indicated by the symbol .DELTA.) is situated on the first page where it may attract attention most or on the last page (a), as shown in FIG. 23(A), no turning bar mechanism is required. On the other hand, in order to locate a color-printed page at another position, it is necessary, for example, as shown in FIG. 23(B), to reverse the sides of the travelling web W3 and further to change its route of travel beneath the route of the other travelling webs W1 and W2 to above the same. It is therefore necessary to provide two turning bars and two bay window rolls (not shown) exclusively for this purpose, and to pass the travelling web W3 therethrough. Thus, here again, the above-described troubles caused by the use of a turning bar mechanism cannot be avoided.